Year	years
1960	46.741981701553435
1961	47.45747214970667
1962	47.9697565267833
1963	48.65304371426095
1964	49.508712564455635
1965	49.86999257926365
1966	50.158373006521145
1967	50.683989624215
1968	51.15068505076246
1969	51.58727276605069
1970	52.1006772939169
1971	52.99843083027691
1972	53.542810732095056
1973	54.32706158302627
1974	54.93115653967738
1975	55.59563668831498
1976	55.863871917919106
1977	57.06173226323419
1978	57.824787099756975
1979	58.5506026027253
1980	59.33439076172919
1981	59.93130576067699
1982	60.45265384863916
1983	61.17476413653978
1984	61.859742272871394
1985	62.582531910776765
1986	63.76057057941025
1987	63.694716168956184
1988	63.419049274007875
1989	64.75469187537584
1990	65.23031113605454
1991	65.25927057290305
1992	65.51806549898666
1993	66.5070280871039
1994	67.39938491216498
1995	67.42104920887188
1996	67.74203136409798
1997	68.05065772455214
1998	67.92299101833444
1999	68.8075430503901
2000	69.30685403323487
2001	69.62661382757067
2002	69.94063602160894
2003	69.98985933879909
2004	70.13519056216137
2005	70.4400639803527
2006	70.89607739125998
2007	71.2555236877846
2008	71.45269053546026
2009	71.87288730111264
2010	72.08711065633791
2011	72.32035791342496
2012	72.34113704594527
2013	72.42624873338497
2014	72.73070684525804
2015	72.89028085013366
2016	73.22839853973673
2017	73.73231984746572
2018	73.84237696407064
2019	73.93930976806196
2020	73.11271121822094
2021	72.98969420675037
2022	73.37368045182963